AMARILLO, Texas — The JetBlue pilot who disrupted a New York-to-Las Vegas flight with an incoherent rant about religion will rely on the defense that he was insane at the time of last month’s incident, according to court documents filed Wednesday by his lawyers.

Clayton Osbon was indicted last week on one count of interfering with a flight crew. The charge, brought against him last month, carries a maximum sentence of 20 years behind bars, as well as a $250,000 fine.

Osbon’s outburst aboard the flight on March 27 prompted his co-pilot to lock him out of the cabin and make an emergency landing in Amarillo, Texas. Several passengers tackled Osbon to the floor of the plane as he made rambling, incoherent statements about religion.

In a motion filed in a court in Amarillo, Osbon’s attorneys notified prosecutors they would contend their client was insane during the incident, the Amarillo Globe-News reported.

The pilot has undergone an examination at a Fort Worth facility to see if he is capable of standing trial. The results have not been released.